Centrifugal switch



' R. s. HARDIN ANDE. w. WIEHLE.

CENTRIFUGAL SWITCH.

APPLICATION FILED FEB. I4, 1921.

1,419,626. Patented June 13,1922.

UNITED STATES PATENT OFFICE.

RAY S. HARDIN AND EDWARD W. WIEHLE, OF CHICAGO, ILLINOIS, ASSIGNORS T0 BIRTMAN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 0F ILLI- NOIS- CENTRIFUGAL SWITCH'.

Specification of Letters Patent. v Patented June 13, 1922.

Application filed February'14, 1921. Serial No. 444,634.

To all 'whom t may concern.'

Be it known that we, RAY S. HARDIN and EDWARD W. IVIEHLE, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Centrifugal Switches, of which the following is a specification.

This invention relates to centrifugal switches and is particularly adapted to be used on the rotors of alternating current motors.

The primary object of. this invention is to provide ay switch which will open with a snap, thereby providing a quick break of electric current through the winding when a predetermined speed is reached.

Another object is to provide a switch having this quick break wherein .the brushes have a rotary movement relative to the contact members. l

These -and other objects are accomplished by our invention, which is fully described. in the following specification and shown in the accompanying drawings, in which Fig. 1 is a perspective view of the end of the rotor equipped with our centrifugal switch, and showing the'same in closed position, and Fig. 2 is an end elevation of the same, showing the switch inv open position.

The rotor1 10 is mounted upon a shaft 11, which may be journaled in the motor frame, (not shown) in any well known manner.l A support 12 is carried by the rotor and is secured to the rotor by means of posts 13,.

and has pivot pins 14 and 15 secured thereto.v A centrifugal member 16 is pivotally mounted upon the pin 15, 'and has at its outergend a slotted opening 17 which is concentric with the pin 15 and through which a screw 18 is looselyin'serted so as to limit the inward and outward throw of the centrifugal member '16.

The inner end of the centrifugal member is extended beyond the pivot pin 15 and carries a pin 19 on which is pivotally mounted one end of a guide rod 20. The opposite end of this guide rod is preferably flattened and passes through va slot in the bent up outer end 21-ofv the brush 22, which is pivotally mounted upon the pin 14. A

.'pring 23 is placed under compression between the end 21 and the enlarged end of the rod 20." l Y is preferably i assume the position shown in F'ig..1` and in. the dottedv lines as shown in Fig. 2, with the brushes 22 held in engagement with the contact members 24 and 25. In this position it will be observed that the direction of the application of the springs 23 is such as to tend to hold the centrifugal member 16 retracted, as shown in thedotted lines in Fig. 2, and at the same time to hold the brushes 22 in engagement with the contact members.

As the motor is -started and gains in speed, the centrifugal mem-ber 16 will. be forced outwardly by centrifugal force until the line of application of the spring 28 will pass through the pivot pin 14 of the brush 22. As -the member 16 continues to move outwardly, the pin 19 will move inwardly until a point is reached where the upward pressure upony the brushes 22'is sufficient to overcome the friction of these parts, and

the brushes will move upward with a snap until they are stopped by the pin 27, as shown in fullvlines in Fig. 2.

It will be observed that in this position the line of action of the spring 23 is never y permitted to pass through the pivot 15, so that the spring 23 always tends to force the centrifugal member 16 to the retracted po-- sition shown in the dotted lines in Fig. 2.

At the instant of starting, the brushes are in engagement' with the contact members 24 and 25, and the current flows therethrough to the starting windings (not shown), in a well known manner. As soon as a predetermined speed is reached, the brushes 22 are-snapped out of engagement,

as previously described, breaking the current which is flowing through the starting windings, and doing it so quickly that no arc of any consequence is able to follow these brushes.

The essence of this invention -is the toggle joint which gives a quick break, thereby preventing arcing, and while the device is .'*30 y is reached and to force said brush out of p 45 a predetermined speed 1s reached, and to shown in connection with a rotor of a motor it will be understood that it is not limited to this specific application, but that it may be used in other relations requiring acentrifugal switch.

While we have shown and described but a single embodiment of our invention, it is to be understood that it is capable of many modifications. Changes, therefore, in

the construction and arrangement may be made without departing from the spirit and scope of the inventlon, as disclosed in the' appended claims,in which' it is our intention to claim all novelty `inherent in our invention as broadly as possible in view of the lprior art.

What we claim as new and desire to secure by Letters Patent is:

l. In a centrifugal switchv for electric motors, a contact member, a supportcarried by the rotor, a centrifugal member movably carriedby said support and movable outwardly by centrifugal. force, a brush movably carried by said support, and a spring operably connecting said centrifugal member i and brush andv tending toi. force. said centrifugaly` member inwardly under all" conditions and operating to hold said brush. in cont/act with said sta tionary member until a'predetermined speed contact with said stationary member at speeds greater",l than said predetermined speed.

@alli a centrifugal switch for electric mof tors, a contact member, a support carried by t said predetermined speed.

' operably connecting sai the rotor, a centrifugal member pivotally mounted on said support and movable outwardly by centrifugal force', a brush movably carried by said stpport, 'and a spring centrifugal member and brush and tending to force said cen-' trifugal member inwardlyy under all condif tions 'and operating to hold said brush in contact with said stationary member` until force said brush out of contact with 'said stationary member at speeds greater than 3. In a4 centrifugal switch for electric mo,-

torsa contact member, a support carried by the rotor, a centrifugal member pivotally mounted on said support and movable out-v y y wardly by centrifugal force, a brush pivot* ally mounted on said support, and 'a com-1( pression spring mounted between the brush and inner end of the centrifugal member, so that as said inner end moves inwardly and the outer end moves outwardly under the action of centrifugal force, the line of action of -said spring passes through the axis of the pivot point of said brush at a predetermined speed and the brush is snapped out of contact withsaid stationary member.

4. In a centrifugal switch vfor electric motors,` a contact member, a support carried by the rotor, a centrifugal member pivotally mounted on said support and movable outwardly byucentrifugal force, a brush pivotally mountedV on said support, a compression springmounted between the brush and inner end ofthe centrifugal member, so that as said innery end moves inwardly and the outer end moves outwardly under the action of centrifugal force, the line of action of said spring passes through the pivot point of said brush at a predetermined speed and the brush'is quickly moved outfof contact with' said stationary member, and a stop preventing outward movementof theA brush.;

from bringing the line of application of said spring through the axis of the pivot lpoint of said centrifugal member.

5. In aA centrifugal. switchffor electric motors, a contact member, a support carried by the rotor, a centrifugal member pivotally mounted on said support and movable outwardly by 'centrifugal force, a brush carried by said support, anda toggle joint having a outwardly under centrifugal force, the line of` action of said'dspring passes through the ,axis of the pivot point of said brush at a predetermined speed and the brush is snapped out vof'conta'ct with said stationary member. 'l .y A

Ars-Q HARDIN. i

EDWARD W, 

